I believe '40 cases had ribs and 112-35 on the outside of the case, but open races I think (I can look at one on the shelf tomorrow to be sure). You have left us to suspect that there aren't even belly production numbers, much less VIN numbers. An interesting piece, no doubt,.. but it's a liability in this state.

I have seen these type of cases on a few occasions and they are always not original numbers. They are replacement cases of about 1942/43 vintage for a 36 to 39 motorcase. Starting in about 1944/45, the replacements still have the early blind races, but the casting # ends with -40. About 20 years ago I purchased 8 NOS sets of knuckle cases and about half were of the style you mention.

You should be able to approximate the manufacture date by the case matching #'s on the bottom and the casting date pad inside each case.

These cases do not always have a typical looking case matching #. I have seen them 3 different ways. The most common is to have the ordinary type number. The second type will have just a 2 digit number. The third will have a single capital script alphabetic.

Good Luck and I hope that I may have helped you out. I currently have case examples of all of the above mentioned odditys and feel free to email me if I can be of additional help. Jerry

Cotten Original motors did not get the ribs until late 1941 for the FL and 1942 for the EL. The previous statement is my opinion based on looking at knucklehead cases fast approaching the 30 year mark. (29 and counting) 1940 and 41 motor cases do not have the raised casting # like the early motors and have the thru/lapable race. Jerry

Thanks Jerry! I stand corrected on the lack of ribs on 40's (my PC is not at my shop with the hardware.) It surprises me that the factory would continue with the 'blind' race design for replacement cases so long after they improved it, particularly since the sprocket shaft and cage assembly differed so little. I do seem to remember the belly production number on these '40s started with 40E instead of 240 like later 61"s. I have recently encountered a '40 with '47 replacements; I assume this because there was no dedication to 61" or 74" in the production number. I hope I am right, as I wrote a letter to this effect to allow the authorities to return the confiscated machine. (Doh! Now that I have pulled my '40 out of the bin, I see it has no cast -35 number either. I guess I should have read my Palmer book.)